In today's competitive environment the bigger brands started offering really good ones for less than that because they realized that there is a big market segment for this.
Without any other introduction you'll find here the reviews of the best built-in dishwashers in the segment of under 500 bucks.
I personally would recommend the EdgeStar Energy Star 18'' because it performed great in my testing and I like the overall design, but any of the other three represent really good alternatives and worthy competitors to the EdgeStar.
Best customer rating
Energy Star 18" Built-In Dishwasher
Model DWE1801B Built-In Dishwasher
DDW1809W-1 Built-In Dishwasher
SB 80 Equator Fullsized Built-In Dishwasher
These are the best four built-in dishwashers if you have a budget of under 500 bucks.
The're not the most advanced ones, nor are they the most silent. You can get a countertop for this money, but rest assured that a built-in, even at this price, will beat it in performance.
The important thing is that they clean the dishes well and are a perfect fit for a small to medium family that cooks at home.
All in all, they represent a good choice when it comes to price-performance ratio.
George Danir and Team